We have developed procedures for oocyte aspiration from the preovulatory follicle, in vitro fertilization, embryo culture and an alternative low tubal ovum transfer surgical procedure allowing in vivo fertilization. Restrospective analysis demonstrated that aspiration of the preovulatory follicle often induced corpus luteum dysfunction. Further, we have assessed cleavage rates of monkey embryos in vitro, finding that their retarded progression may be a major obstacle in successful in vitro fertilization with embryo transfer. To test for inherent versus environmental deficiencies that may impair embryonic development before implantation, we devised an egg-embryo chamber that is used in the abdomen. Passage of peritoneal fluids nurtures the embryo so that normal development can occur.